INHIBITION OF PLA₂, COAGULANT AND HEMORRHAGIC ACTIVITIES OF Bothrops alternatus VENOM BY Schizolobium parahyba (Caesalpinoideae) EXTRACT

MENDES, M.M., VALE, L.H.F., GEBRIM, L.C.P.C., HAMAGUCHI, A., HOMSI-BRANDEBURGO, M.I.

Instituto de Genética e Bioquímica, Universidade Federal de Uberlândia, MG, Brazil

Snake venoms are complex mixtures of proteins which cause several biological effects Vegetal extract represent an attractive source as an alternative substitute for antiserum.We reported the effects of the crude aqueous extract of leaves (EVF) from Schizolobium parahyba to neutralize the hemorrhagic, coagulant and PLA₂ activities induced by Bothrops alternatus venom.TheEVF was prepared by mixing the leaves with destiled water and centrifuged at low rotation for 20 min/4°C and the supernatante was lyophilized and stored at -20°C. Hemorrhagic activity was tested by intradermal injection of 2 MHD (minimun hemorrhagic dose, 10.12 mg) in Swiss male  mice (n=6, 30g), distribuited in 3 groups,.G1: only VB, G2: only EVF, G3: VB+EVF/1:20 (w/w).The coagulant activit on bovine plasma was carried out at 37ºC, by using 10 mg of venom (VB) (positive control) and 50mg of EVF(negative control).The VB+EVF was used as group test in the ratios 1:1, 1:2 and 1:5 (w/w), respectively. The PLA₂ activity was determined by  potenciometric titration effected on egg yolk as substrat, in presence of the sodium deoxicholic and calcium cloride using the same ratios of the coagulant activity. The EVF was able to neutralize 100% of the hemorrhagic activit in the ratio 1:20. The coagulant and PLA₂ activities were inhibited in a dose-dependent curve, reaching 100% in the ratio 1:5 (w/w) for both. Our results clearly indicate that the aqueous extract of the leaves from Schizolobium parahyba contains compounds capable to neutralize proteolytic and PLA₂  activities induced by Bothrops venoms.

Supported by CNPq, FAPEMIG and UFU. 

CORRESPONDENCE TO:

Mirian Machado Mendes, Rua Planaltina;284, Araguari, MG, CEP: 38441080, Brasil, Email: nairimmachado@bol.com.br